Re: Possibility of adding -march=native to x86

[Adrian Bunk <bunk@kernel.org>]

On Fri, Oct 26, 2007 at 11:41:18AM +0100, Pádraig Brady wrote:
> Adrian Bunk wrote:
> > On Thu, Oct 25, 2007 at 09:12:45PM +0100, Michael Lothian wrote:
> >>> The MPENTIUM4 option does not only set -march=pentium4, it also enables
> >>> several other options in arch/i386/Kconfig.cpu resulting in better
> >>> performance.
> >> How about an autodetect to set the right options here too using cpuid?
> >>
> >> With a warning of course that the code produced will be specifically
> >> for the native cpu that it's compiled on.
> > 
> > If you don't know or can figure out yourself the CPU you have, you'd 
> > better not compile your own kernel...
> 
> There also is the added variable of what your version of gcc supports.
> The kernel gcc options would have to be the highest common factor.
> See also http://www.pixelbeat.org/scripts/gcccpuopt

arch/i386/Makefile.cpu already does more or less the same.

> Pádraig.

cu
Adrian

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